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Risk for Urinary Tract Infections

The amount of acid in a person’s urine, and small molecules related to diet, may help predict how likely it is that an individual will develop a urinary tract infection. Conventional wisdom in medicine has favored the idea that acidic urine should be better at restricting bacterial growth than less acidic urine. But Washington University School of Medicine researchers found that when a person’s urine was closer to the neutral pH value of pure water, it was better at restricting bacterial growth than more acidic samples were, meaning people with less acidic urine may be less likely to develop infections.

RESEARCHERS AT WASHINGTON UNIVERSITY SCHOOL OF MEDICINE IN ST. LOUIS HAVE TAKEN STEPS TO IDENTIFY WHAT PUTS INDIVIDUAL PATIENTS AT THE GREATEST RISK FOR RECURRENT URINARY TRACT INFECTIONS, OR UTIs. IT TURNS OUT THAT THE ACIDITY OF URINE, ALONG WITH THE PRESENCE OF SMALL MOLECULES RELATED TO DIET MAY INFLUENCE HOW WELL BACTERIA CAN GROW IN THE URINARY TRACT. JIM DRYDEN REPORTS…

URINARY TRACT INFECTIONS, OR UTIs, ARE ONE OF THE MOST COMMON INFECTIONS THAT PHYSICIANS TREAT, AND IT’S GETTING MORE COMMON FOR SOME OF THOSE INFECTIONS TO BE RESISTANT TO THE ANTIBIOTICS USED AS STANDARD THERAPIES, ACCORDING TO WASHINGTON UNIVERSITY RESEARCHER JEFFREY HENDERSON.

(act) :22 o/c a result

A lot of patients who get UTIs are really prone to have them

recur. And this is something – you know, ask any family physician,

they’ve seen patients with the same problem. They tend to have

recurrent UTIs over and over again, and it’s unclear why this

happens. And what often ends up happening is the patient gets

repeated rounds of antibiotics as a result.

SO HIS RESEARCH TEAM LOOKED AT URINE SAMPLES FROM OLD PEOPLE AND YOUNG PEOPLE, MALES AND FEMALES TO IDENTIFY DIFFERENCES. THEY FOCUSED ON A PROTEIN CALLED SIDEROCALIN THAT HELPS FIGHT INFECTIONS BY DEPRIVING BACTERIA OF THE IRON NEEDED FOR GROWTH.

(act) :12 o/c in others

Siderocalin worked sometimes but not all the time. It depended

on who gave the urine specimen. So basically, siderocalin works

in some people, but not in others.

ONE FACTOR THAT DETERMINES WHICH PEOPLE, HENDERSON SAYS, IS THE URINE’S ACIDITY.

(act) :11 o/c work better

Classically, physicians have often sought to “acidify” the

urine as a way to keep bacteria away, and while that actually

may work for some kinds of bacteria, in this particular case,

it was the other way around. A higher pH helped this innate

immune protein work better.

BUT THERE WERE OTHER FACTORS INVOLVED, TOO. ONE OF THOSE INVOLVED A CLASS OF MOLECULES CALLED AROMATIC METABOLITES THAT, HENDERSON SAYS, ALSO INFLUENCED HOW EFFECTIVE SIDEROCALIN COULD BE.

(act) :09 o/c to work

PH was one piece of the puzzle. Aromatic compounds were the

second, so those two things worked together to allow this

protein to work.

HE SAYS SOME PEOPLE HAD THE IDEAL COMBINATION, BUT OTHERS DID NOT. ANOTHER KEY FACTOR IN THE RISK FOR RECURRENT UTIs IS RELATED TO DIET, BUT HENDERSON SAYS IT ISN’T AFFECTED BY SOMETHING AS SIMPLE AS WHAT WE EAT AND DRINK. RATHER, HE SAYS THE AROMATIC METABOLITES THAT END UP IN URINE ARE INFLUENCED BY THE RELATIONSHIP BETWEEN WHAT WE EAT AND THE TYPES OF MICROBES THAT LIVE IN OUR GUTS.

(act) :09 o/c the intestine

These metabolites don’t come directly from the diet. They are,

themselves, from molecules that are converted by bacteria in

the intestine.

AND HE SAYS A MORE COMPLETE UNDERSTANDING OF HOW ALL OF THESE FACTORS COME TOGETHER TO INFLUENCE RISK FOR UTIs SHOULD HELP DOCTORS MORE EFFECTIVELY TREAT AND EVEN PREVENT THE INFECTIONS IN THOSE PATIENTS AT THE GREATEST RISK FOR RECURRENT PROBLEMS.

(act) :10 o/c with UTI

We would like to be able to use these results to come up with

better ways to treat people with UTIs. And these may be non-

antibiotic ways of treating people with UTI.

HENDERSON AND HIS COLLEAGUES REPORT THEIR FINDINGS IN THE JOURNAL OF BIOLOGICAL CHEMISTRY. I’M JIM DRYDEN

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